Model Output Discussion - Into 2024

[Don]

Just now, Bricriu said:

It's funny in December  when we wanted it more active in phase 7 it failed to oblige. Now that it might be stronger in phase 4 than anticipated  it could be a hindrance  to maintaining blocking.  Can we ever catch a break.

Rarely it would seem these days, but as I said earlier, more twists and turns to come!

[feb1991blizzard]

Just now, Met4Cast said:

Not *too* worried about that yet given the scatter & uncertainty that has suddenly been thrown into the mix, we do often see modelling too eager to remove blocking & that could be what's at play here too, especially given the spread on how the blocking evolves in the first place. 

I wonder if the uncertainty with the MJO is playing a part here along with the current minor warming in the strat. 

Just wondering about comment on twitter the other day (think it may have been Liam Dutton) that because of the topography, modelling of Greenland highs is poor, i wonder how the met office distinguish between a real GH (ie - one thats likely to verify) and a faux one, because they were rock solid about Dec 09, Nov and Dec 2010 from a long way out, how did they know they were not just going to implode within D8-10.

[northwestsnow]

Longer term aside fingers crossed for those further South over the coming days ...

Looks cold enough now.. 

Edited January 6 by northwestsnow

[Cymro]

42 minutes ago, Kentspur said:

So much better than a failed dry  Northerly which gets threatened by the Iberian high everytime it attempts to move south of the Midlands think im going to stick to the snow potential in the reliable period Monday for now too far away still to know about this period! Exciting times fellow Southern/Southeasterners

The definition of IMBY here! 

Most northerlies progged thus far have been very unstable and would bring copious amounts of Snow UK wide if verified! 

[Don]

3 minutes ago, northwestsnow said:

I'm indifferent to the GFS ,I'm happy UKMO is on board but EC has spooked me ..

I'd rather say little when I'm spooked because dejavu is the buzzword I'm feeling right now..

Really hoping for upgrades in the morning,it's not impossible but the trend hasn't been positive through today

.

Coupled with the more uncertain Metoffice outlook today, I think that's fair to say!  Fingers crossed for a turn for the better tomorrow!!

[Met4Cast]

We've certainly come along way from this run just 2 days ago..

But.. we're still not quite done yet. It's a shame so much uncertainty has been injected into the modelling because things were counting down so well but I guess it wouldn't be a cold UK weather chase without some sort of spanner being thrown in somewhere along the lines. We need to watch the block across Greenland and hope modelling has just gone too far in the opposite direction with underplaying it, often is the case. 

[Day_9]

1 hour ago, Battleground Snow said:

That arctic high could push the entire vortex south here

Special synoptics

 

Would be a once in a lifetime if it happened, but it’s one run amongst many every day and it’s 11 days out….. they do rather prod the imagination.  This sort of chart would very quickly become misery for millions once the initial novelty was out of the way.

[weathercold]

A clear backward trend today to anything sustainable re cold /snowy conditions, of that there is no doubt.

When you look back at the rock solid ensembles and models from a week ago and now look at where we are at, it’s sobering to see we have really taken a significant step back here. Deep down I always suspected we would, the UK doesn’t really do bitter cold snowy spells for any length of time, rarely anyway. Tough to take this but I suspect the ship is sailing fast ….in the wrong direction sadly.

[Wold Topper]

I doth my cap to some of you guys whom spend 18hrs a day on here, its an admirable dedication to a hobby that so often (in winter) leads to disappointment, after following many a chase these background signals and current synoptics may for once lead to a winter nivarna that many crave.

[Don]

Just now, weathercold said:

A clear backward trend today to anything sustainable re cold /snowy conditions, of that there is no doubt.

When you look back at the rock solid ensembles and models from a week ago and now look at where we are at, it’s sobering to see we have really taken a significant step back here. Deep down I always suspected we would, the UK doesn’t really do bitter cold snowy spells for any length of time, rarely anyway. Tough to take this but I suspect the ship is sailing fast ….in the wrong direction sadly.

As I said a week or so ago, the LRM's in the run up to winter were always forecasting a 'back loaded' season, so perhaps the best of winter will be reserved for February? 

[Zero Visibility]

Today might have provided much uncertainty, we can all still dream about hitting the jackpot once again in this country, and who knows tomorrow is a new day. I will try to lift some spirits. ECM= Euphoria Come Morning! Let's hope.

[MATTWOLVES 3]

3 minutes ago, weathercold said:

A clear backward trend today to anything sustainable re cold /snowy conditions, of that there is no doubt.

When you look back at the rock solid ensembles and models from a week ago and now look at where we are at, it’s sobering to see we have really taken a significant step back here. Deep down I always suspected we would, the UK doesn’t really do bitter cold snowy spells for any length of time, rarely anyway. Tough to take this but I suspect the ship is sailing fast ….in the wrong direction sadly.

Clear and backwards trend? 

1..met update still very positive.

2. Some good op runs throughout the day and still good ens support.

3. Mogreps trending colder again.

4. Still.good anomolies.

5. Positive noaa update.

6. NWP chops and changes on regular basis when it comes to this kind of set up.

7.minor but significant warming of the strat currently underway which will cause yet more model headaches.

8. The UK has had numerous severe cold snaps over the years..yes more Intense many years ago but cold patterns come in cycles...ie 2009 then 2010...then 2013..then 2018..Yet far to many base previous failures as the benchmark in saying it won't come off cause it rarely does.. weather is a science not something that develops out of good or bad luck and a hunch.

STILL LOTS TO BE POSITIVE ABOUT! 

[Geordiesnow]

10 minutes ago, Met4Cast said:

We've certainly come along way from this run just 2 days ago..

But.. we're still not quite done yet. It's a shame so much uncertainty has been injected into the modelling because things were counting down so well but I guess it wouldn't be a cold UK weather chase without some sort of spanner being thrown in somewhere along the lines. We need to watch the block across Greenland and hope modelling has just gone too far in the opposite direction with underplaying it, often is the case. 

Well no wonder, look at the timeframe!! I think the models have handled this quite well and the runs have been fairly solid. The uncertainty starts how much retrogression we shall see and how strong do the floodgates open, some runs are better than others for sure but that is to be expected really.

A snowy set up is far from guaranteed at this stage.

For those down south, let's see what develops in the next 48 hours because that could potentially be the only snow risk that actually develops during this period.

[Met4Cast]

For what it's worth the multi-ENS which comprises of multiple model ensembles seems rather solid for a proper cold spell from this northerly. I often find this to offer the best guidance at times of uncertainty.

[Day_9]

Mega lolz

 

 

[damianslaw]

4 minutes ago, Day_9 said:

Mega lolz

 

 

18z doing its usual stuff, yesterday's was a snowy freeze, today it rolls the atlantic through.. always wonder what it takes.. looking at, it looks plain odd. 

Edited January 7 by damianslaw

[Beanz]

10 minutes ago, Met4Cast said:

For what it's worth the multi-ENS which comprises of multiple model ensembles seems rather solid for a proper cold spell from this northerly. I often find this to offer the best guidance at times of uncertainty.

How does it compare to the same graph from 3 days ago though? 

[Met4Cast]

7 minutes ago, Beanz said:

How does it compare to the same graph from 3 days ago though? 

Unfortunately there's no archive so I'm not sure but I doubt it would have looked too different, the ensembles weren't suggestive of deep (sub -10C) cold even 3 days ago really.

[WolfeEire]

19 minutes ago, Met4Cast said:

For what it's worth the multi-ENS which comprises of multiple model ensembles seems rather solid for a proper cold spell from this northerly. I often find this to offer the best guidance at times of uncertainty.

Have you a link to this please @met4cast?

[Met4Cast]

2 minutes ago, WolfeEire said:

Have you a link to this please @met4cast?

It's part of NetWx Extra so if you're not subscribed to that this link wont work;

Netweather Extra

WWW.NETWEATHER.TV

 

[terrier]

However we dress today up it’s not been great ECM has been showing not great for the last 3 runs now. Seems as though the pub run has been on the lemonade tonight. Definitely not trends we won’t to see into tomorrow. Still very sceptical about any deep freeze and heavy snowfall. Let’s see what tomorrow brings. 

[Rain All Night]

Can the machine learning models at 12z T+240h give us any reassurance?

The first row of charts below is the regular ECM 12z op, which you can compare to the Meteociel charts above to help you get used to looking at the machine learning model charts (the subsequent five rows) in the ECM website's formats.

The T850 shading on the ECM website's charts is grouped in intervals of 4C. The dark green colour represents the interval from -4C to -8C, so you can look at it as being the threshold between average temps and proper cold.

ECM has collapsed the pattern as we know, AIFS looks like cold has made it down from the north and is covering the northern half of Britain

FourCastNet looks a bit less cold than AIFS as it looks like the high has not gone as far north, FuXi looks as good as AIFS or maybe slightly better

GraphCast looks like a complete fail with a mild low having pushed up over the UK, Pangu-Weather looks like it might have delivered the best northerly of the lot

Verification scores of these models (IFS is regular ECM):

Edited January 7 by RainAllNight

[Mizzle]

Normally I can work out the acronyms but GH has me stumped! Help!  

Edited January 7 by Mizzle
Typo

[*Stormforce~beka*]

1 minute ago, Mizzle said:

Normally I can work out the acronyms but GH has me stumped! Help!  

Greenland High ... If I'm right ...!

[Mcconnor8]

1 minute ago, *Stormforce~beka* said:

Greenland High ... If I'm right ...!

If you hover over it then Netweather tells you that you are